Financial Innovation Way of Avoiding Risk of Climate Disasters in Food Production:Weather Index Insurance

Climate change will lead to a variety of climate disasters, and climate disasters have a greater impact on China＇s food production. Weather index insurance is a new financial way to avoid risk of climate disasters effectively in China＇s food production. Firstly, the relationship between weather index insurance and food production in China was elaborated, and then the development status, advantages and disadvantages of weather index insurance in China at present were analyzed. Finally, some countermeasures against the problems of weather index insurance in China were put forward.

Weather index insurance for wind energy

As China vigorously promotes the development of new energy,photovoltaic power curtailment and wind power curtailment have been effectively resolved.At the same time,the yield from new energy power generation is becoming an important factor that affects the scale of investment in new energy.This paper focuses on the weather risks faced by wind power producers.By studying current research on weather index insurance in China and abroad,the functions and design methods for weather index insurance have been clarified.In addition,the feasibility of wind-power generation index insurance is discussed.The calculation methods for wind power generation index and the weather index insurance pricing methods for wind power enterprises are proposed.A weather index insurance model for wind power generation was established.The rationality and feasibility of the weather index insurance model proposed in this paper were verified using data from an existing power plant.The simulation results show that wind power enterprises can effectively avoid economic losses caused by weather risks through weather index insurance.

Farmers' Risk Preferences and Agricultural Weather Index Insurance Uptake in Rural China

The purpose of this study is to investigate the effect of farmers' risk preferences on their decisions to purchase the agricultural weather index insurance based on the evidence from a household survey and field experiments conducted in Yongqiao District,Suzhou City of Anhui Province in China.Our empirical results show that farmers' risk aversion significantly increases the probability of their decision to buy weather index-based crop insurance.Other factors that significantly influence weather index insurance participation decisions include farmers' subjective beliefs on the probability of crop losses,farming experience,education level,farm size,and their household income.The empirical results of this study can provide helpful insights for policymakers and local insurers to further improve farmers' participation in weather indexbased crop insurance.

Performance of Temperature-Related Weather Index for Agricultural Insurance of Three Main Crops in China

In this study, two categories of weather index—absolute index and relative index—for chilling injury and heat damage of three main crops in China were assessed to identify insurable counties. First, correlations between selected weather indices and yield losses were examined for each county. If a correlation was significant, the county was categorized as ‘‘insurable'' for the corresponding hazard or index. Second, the spatial distribution of insurable counties was characterized and finally, their correlation coefficients were analyzed at various spatial scales.The results show that the spatial patterns of insurable areas varied by categories of weather indices, crops, and hazards.Moreover, the weather indices based on relative threshold of temperature were more suitable for chilling injury in most regions, whereas the indices based on absolute threshold were more suitable for heat damage. The findings could help the Chinese government and insurance companies to design effective insurance products.

Farmers’Demand for Informal Risk Management Strategy and Weather Index Insurance:Evidence from China

In the absence of formal risk management strategies,agricultural production in China is highly vulnerable to climate change.In this study,field experiments were conducted with 344 households in Heilongjiang(Northeast China)and Jiangsu(East China)Provinces.Probit and logistic models and independent sample T-test were used to explore farmers’demand for weather index insurance,in contrast to informal risk management strategies,and the main factors that affect demand.The results show that the farmers prefer weather index insurance to informal risk management strategies,and farmers’characteristics have significant impacts on their adoption of risk management strategies.The variables non-agricultural labor ratio,farmers’risk perception,education,and agricultural insurance purchase experience significantly affect farmers’weather index insurance demand.The regression results show that the farmers’weather index insurance demand and the influencing factors in the two provinces are different.Farmers in Heilongjiang Province have a higher participation rate than those in Jiangsu Province.The government should conduct more weather index insurance pilot programs to help farmers understand the mechanism,and insurance companies should provide more types of weather index insurance to meet farmers’diversified needs.

Estimating the properties of weathered bedrock and pile-rock interaction from the geological strength index

The effect of variable rock mass properties on pile-rock interaction poses a great challenge to the design of stabilizing piles and numerical analysis of pile-rock interaction. The paper presents a novel method to estimate the properties of weathered bedrock, which can be applied to routine design of landslide-stabilizing piles for collivial landslides. The Ercengyan landslide located in the Three Gorges Reservoir, China, is the area of interest for this study. A geological investigation and triaxial tests were conducted to estimate the basic parameters, including Geological Strength Index(GSI), uniaxial compressive strength σ_(ci) and Hoek-Brown constant m_i of intact bedrock in the study area. Hoek-Brown criterion was used to estimate mechanical properties of the weathered rock, including elastic modulus E_m, cohesion c, friction angle Φ, and normal ultimate lateral resistance p_(max). A parametric study was performed to evaluate the effect of parameterizations of GSI, σ_(ci) and m_i on the bedrock properties and p-y curves. The estimated rock mass properties were used with PLAXIS 2D software to simulate pile-rock interaction. Effect of GSI on stress at the pile-rock interface and in the rock, pile bending moment, pile shear force, and p-y curve were analysed.

福建漳州平和柚天气指数保险产品设计与定价

柚产业是福建省漳州市平和县的支柱产业,为分散当地柚生产的经营风险,基于福建省漳州市平和县1985−2022年柚产量及对应年份3月中旬至8月上旬的天气数据,将柚单产数据分解成趋势单产和气象单产,并调整单产数据使其转化到2024年的生产力水平下的单产,选用核密度估计法拟合该序列的概率密度函数并用于纯费率厘定;而后利用调整后单产数据和天气数据进行相关性分析,筛选显著的天气指数。结果显示:4月中下旬降雨量指数与调整后单产的线性关系最为显著。对于2024年约定的保障产量51000 kg·hm^(−2)和保险价格2.8元·kg^(−1),即每667m^(2)保险金额为9520元,厘定纯费率为4.0191%、保险费率为4.6220%;对于降雨量指数RI的保险赔付触发值160 mm以及RI的8个分级赔付区间,分别计算得到了对应的赔付事件发生概率,并给出了对应的赔付金额计算公式。

我国本土气温指数期货产品的研发设计——源于京津冀“首都经济圈”核心功能区的气温数据

我国幅员辽阔,对天气变化非常敏感,迫切需要对天气风险进行有效管理,以消除或减少天气风险对各行业的不利影响。从产品研发设计视角出发,以京津冀“首都经济圈”核心功能区为例,参考国外成熟产品,对我国本土气温指数期货产品进行合约设计和模拟定价,根据行业需求阐述产品的应用价值,提出产品在天气风险管理中的显著作用。研究贡献有,搭建起我国本土气温指数期货产品的研发体系;基于国外成熟市场规则构建出符合我国国情的气温指数期货产品标准化合约框架;运用ARMA模型构建出精确度高的气温预测模型;采用蒙特卡罗模拟法制定出气温指数期货两款产品价格;明确产品的应用推广需求和风险管理作用。

恶劣天气下机场离场航班运行韧性评估及恢复

为保障恶劣天气下机场整体性能,科学评估机场离场航班运行韧性,提高航班恢复能力,从而有效缓解天气的影响。给出机场离场航班运行定义,从机场离场航班运行系统性能出发,分析航班离场延误时间、离场总延误时间、离场航班正常率和机场离场航班运行系统综合韧性指数4个指标,对系统在恶劣天气条件下的韧性变化进行评估;提出机场离场航班运行系统性能恢复策略,利用遗传算法对离场延误航班进行优化排序;以2012年北京首都国际机场“721”特大暴雨事件为实例进行数据分析,得到暴雨影响下首都机场的性能指标和韧性指数,对比分析机场离场航班运行系统性能及韧性水平变化。研究结果表明:受暴雨影响,机场离场航班运行系统综合韧性指数由0.457 3下降到0.062 8,暴雨减小后上升到0.222 3;在进行航班优化排序后,离场航班总延误时间减少了24.85%,优化后机场性能恢复速度提升了13.89%,优化后的机场离场航班运行系统最小韧性指数提升了13.38%,系统性能优先恢复至初始状态,表明所提恢复策略有效。

安徽主要粮食作物天气指数保险模型研究与应用

气象灾害是农业生产面临的主要风险之一,给农业安全生产带来巨大损失。农业保险是农业保障体系的重要组成部分,是有效分散农业风险或弥补灾害损失的重要救灾手段之一。20世纪90年代后期出现的天气指数保险,因其客观、标准化和流通性强等特点在全球引起广泛关注、研究与应用。本文在回顾了国内外天气指数保险技术的发展历程基础上,详细分析了天气指数保险与传统农业保险的差异,以及各自的优势与劣势;以安徽粮食作物(冬小麦、一季中稻、夏玉米)生长过程中特定农业气象灾害的天气指数保险为例,介绍天气指数模型研制与产品开发。通过天气指数农业保险产品在安徽多年实践应用,探索天气指数模型的改进方法,以降低基差风险;并对天气指数保险未来发展进行探讨与展望。

琼中地区中三叠世黑云母二长花岗岩成壤过程的量化指标表征

土壤是地球关键带的重要组成部分,是岩石风化的结果,是连接岩石圈、生物圈、大气圈和水圈的纽带,其形成、发育和功能将深刻影响地球生态系统的可持续性(朱永官等,2015)。由岩石到土壤的风化过程中,土壤过程是控制地球关键带中物质、能量、信息流动与转化的重要节点。受成壤母质、气候等因素的影响,元素的活动性表现出不同的特点规律。不同学科通过不同量化指标表征成壤过程中元素的规律。

黄河口大闸蟹高温天气指数保险产品设计与研发

利用1981-2021年东营国家气象观测站逐日气温观测数据、2019-2021年黄河口农业水域小气候观测站逐日气温和水温观测数据以及2004-2021年东营市黄河口大闸蟹产量数据,采用滑动平均法分离气象产量后计算气象减产率,分析大闸蟹生长周期内温度和减产率的关系,筛选极显著相关的高温天气指标,构建高温指数-灾损模型,确定灾害损失阈值,设计研发黄河口大闸蟹高温天气指数保险产品。结果表明:随着生产技术的提高,黄河口大闸蟹增产明显;受不同年份气象条件差异影响,黄河口大闸蟹气象减产率波动明显,减产率与≥35℃有效积温日均值呈极显著正相关(P<0.01)。结合1981-2021年高温气象资料,确定≥35℃的有效积温日均值即高温指数达1.893℃·d,可导致大闸蟹减产12.4%;依高温指数-灾损模型可进一步将黄河口大闸蟹高温灾害分为轻度、较轻、中度、较重和重度五级,并取高温指数≥1.529℃·d作为理赔触发值计算可发生赔付年份的平均赔付金额为294.04元667m^(−2),赔付金额范围为58.59~651.00元667m^(−2);黄河口大闸蟹高温天气指数纯保险费率为6.61%,保费为43.03元667m^(−2)。

安徽省强对流天气灾害的时空分布特征研究

文章基于1984—2009年安徽省75个县(市)强对流天气灾害的出现次数和灾情情况等资料,以受灾人数、死亡人数、受伤人数、倒塌房屋、损伤房屋、农作物受灾面积、电力倒杆、直接经济损伤、农业经济损失等9个灾情要素,通过线性组合法构建了强对流天气灾害的综合灾损指数,并依据灾损指数确定了强对流灾害的危害程度,分为一般、较重、严重、特重4个等级。结果表明:1984—2009年安徽地区的强对流天气灾害的年出现次数和年灾损指数总体呈线性上升趋势,较重、严重、特重等级灾害表现出增长趋势;安徽省强对流天气灾害频发的月份是6—7月,夏季是灾害最频发的季节;皖北地区的灵璧县、砀山县、萧县是强对流天气灾害最严重的地区。该研究可为安徽省的强对流天气防灾减灾工作提供参考。

白鹤滩水电站峡谷地形区的风特征研究

位居世界第二大的白鹤滩水电站地处金沙江下游峡谷区,频繁的大风给水电站建设和运行带来了严重影响。掌握水电站坝区大风变化规律,评估峡谷地形对风速的作用,有利于基于周围风场监测和预警峡谷区大风。根据水电站及周边观测资料,对坝区风的变化特征和峡谷地形作用进行了分析。(1)峡谷区最高频率的风向和最大平均风速的风向均为顺着峡谷的偏南风或偏北风,且偏北风频率达55%以上,峡谷锁定了流经气流。(2)坝区大风多发生在干季11月—次年5月,且夜间至清晨大风频率比日间高。干季峡谷风效应强,尤其在19时—次日08时。雨季峡谷风效应降低,局地山谷风增强,表现为山风比谷风持续时间长,08时和18时是山风和谷风交替时间。对应干季和夜晚大风频繁,说明峡谷风效应是影响大风的关键因子。(3)通过狭管效应分析马脖子和葫芦口大桥两个站之间的风速关系,表明峡谷地形使马脖子站风速加强为葫芦口大桥站的1.27倍。利用多种拟合方法建立的两站风速关系表明,当葫芦口大桥站为5 m·s^(-1)以下低风速,各方法都难以拟合峡谷区的风速,当风速在5.0~11.5 m·s^(-1)时,狭管效应对风速拟合最优,准确率超过70%,对11.5 m·s^(-1)以上强风速,多项式拟合效果较优,准确率接近65%。

生物防治与化学防治协同处理防治柑橘全爪螨的温室试验

通过对在重庆市潼南区柏梓镇潼南柠檬脱毒种苗繁育中心的4号大棚中设置的6个处理,在化学防治的基础上选择用药后的不同时间释放捕食螨,以探究生-化协同防治柑橘全爪螨的效果.试验结果表明,施用阿维菌素后第6 d释放捕食螨对柑橘全爪螨的防效最好,虫口减退率和防治效果均可以达到98%以上;且相较于单一施用化学农药持效期更长,约为1.5月,而单一施用化学农药持效期只能维持在10 d左右.由气象因子数据和柑橘全爪螨发生动态相关性分析结果可知,施用化学农药后可提高柑橘全爪螨种群对高温的抗逆性;施用阿维菌素后第6 d释放捕食螨天气积分指数对柑橘全爪螨的影响最大,说明微气候也会对柑橘全爪螨的防治产生影响.研究结果为柠檬产业害螨绿色防治提供了更精细化的方案.

基于TLE数据的大气密度反演与校正

用于航天器轨道预报的热层密度模型普遍存在30%左右的误差,影响LEO卫星的精密轨道确定和载荷控制。基于低轨航天器平运动变化与大气密度的关系,使用GRACE(gravity recovery and climate experiment)卫星TLE数据反演2003、2007年沿轨大气密度,通过比较反演值、模型值和实测值的关系分析误差产生原因,使用对数正态分布拟合密度比值。通过分析太阳辐射、地磁指数对大气密度变化的影响,提出一种基于空间环境指数的热层大气密度模型校正与预报方式。使用该方法对2003、2004、2007、2008年的MSIS86模型计算密度进行修正,将模型平均相对误差从33.33%~59.62%降低到11.55%~15.13%,太阳活动低年改进量是高年的1.5~2倍。对2009年经验模型结果进行预报校正,将预报误差降低36.49%,提高了模型精度。

六春湖摄影气象指数预测评价研究

气象条件对旅游摄影有较大影响。为充分挖掘六春湖“气象景观”资源,根据六春湖景区多年降雨量、风速、能见度和相对湿度等气象数据资料,分析了六春湖山地基本气候特征,划分了摄影气象指数影响等级,建立了六春湖摄影气象指数预测模型。结果能为六春湖景区的游客和摄影爱好者提供可靠的摄影创作条件依据,拓宽了六春湖景区应用气象服务内容。

南漳县西部梁山组富锂黏土岩物源区特征

随着光伏产业和新能源汽车产业的蓬勃发展,国内外锂资源需求持续增加,黏土型锂矿逐渐成为矿产勘查的重点。经地质调查,南漳县西部梁山组黏土岩存在锂的超常富集现象,具备形成独立锂矿床的潜力,而梁山组富锂黏土岩物源特征、沉积环境和成矿规律的研究仍为空白。因此,有必要研究南漳县西部梁山组富锂黏土岩物源特征,以进一步揭示其源区地质特征,为后续找矿工作提供有效指导。经测定,南漳县西部梁山组富锂黏土岩样品Al_(2)O_(3)/TiO_(2)比值为14.45~37.69,平均值为27.68;K_(2)O/Al_(2)O_(3)比值为0.0017~0.0206,平均值为0.0098;Cr/Zr比值为0.1449~0.3519,平均值为0.2775。结果表明,黏土岩物源区主要为长英质岩石。La/Sc-Th/Co图解、Zr-TiO_(2)图解中,所有样品点均落在长英质物源区,显示物源的单一性。大多数样品的化学蚀变指数(Chemical Index of Alteration,CIA)、化学风化指数(Chemical Index of Weathering,CIW)均在90以上,说明源岩经历强烈化学风化作用。

沧州地区春霜冻特征及短期预报方法的研究

为提早做出春霜冻预判以减少对农作物的危害,利用2016-2023年沧州市春季气象资料,采用皮尔逊相关系数、TS评分等方法,对沧州市春霜冻特征和预报指标进行了统计分析及检验。结果表明,沧州市春霜冻发生在3月至4月,结束日期主要在3月下旬-4月上旬,多发生在晴朗、软风、低湿的天气背景下,空间上呈西多东少的特征。以单因素最低气温判定春霜冻是否发生时,多年平均差值(最低气温与最低地温)并非是最优指标,大多数气象观测站表现为前者低于后者。在日最低气温相同的情况下,天气状况和湿度是影响霜冻形成的关键因素,天气越晴好,湿度越小,越容易形成霜冻。加入天气状况和湿度因素后,以最优指标预报春霜冻时全区TS较单因素时提高了7%左右。检验证明,根据最低气温、天气状况、湿度,采用最优指标查表法预报春霜冻的预报效果更好,比普通查表法更适合应用在沧州市春霜冻预报中。

Weathering and soils formation on different parent materials in Golestan Province,Northern Iran

Geochemical,mineralogical,and micromorphological characteristics of soils and their relevant parent rocks including loess,ignimbrite,sandstone and limestone were investigated to identify the soil-parent material uniformity and the weathering degree of soils in Golestan Province,northern Iran.Highly developed Calcixerolls and moderately developed Haploxerepts were formed on loess and limestone,respectively.In contrast,the soils formed on ignimbrite and sandstone were nondeveloped Entisols.Illite was the dominant clay mineral found in ignimbrite and sandstone in both the A horizon and parent material.In loess derived soils however,smectite was dominant especially in the Bt horizon compared to its parent material indicating partly to its pedogenic formation.In limestone,illite and vermiculite were dominant both in the A and C horizons.Ti/Zr ratio proved that the studied soils were closely related to their underlying parent materials geochemically.Chemical index of alteration(CIA),micromorphological index of soil development(MISECA),smectite/illite+chlorite ratio and magnetic susceptibility were applied to investigate the degree of soil development.Results showed that the most and the least developed soils were those formed on loess deposits and limestone,respectively.Application of the different geochemical and pedogenetic approaches was proved to be useful in identifying the relevance of soils to their underlying parent materials and also their degree of development.